The triglyceride-waist circumference index is a valid biomarker of metabolic syndrome in African Americans

Introduction

Racial disparities in health care are pronounced in the US especially as it relates to minorities, such as African Americans (AAs).

The issue of differential health outcomes based on race clearly pertains to the area of cardio-metabolic disorders.

It has been shown, using cut points for non-Hispanic whites (NHWs), that the hypertriglyceridemia waist (HTGW) phenotype, the simultaneous presence of increased waist circumference (WC) and hypertriglyceridemia, is strongly associated with cardio-metabolic risk, metabolic syndrome (MetS), type 2 diabetes mellitus (T2DM) and atherosclerotic cardiovascular disease (ASCVD).

This was supported by many but not all studies in various parts of the world. Based on a preliminary study of only 66 men, HTGW was not found to be a valid measure of the metabolic triad and ASCVD in AAs. Due to the wide variation in waist circumference criteria in different races, investigators have instead quantitatively defined the TG.WC index as the product of WC and TG, using both as continuous variables. This new TG.WC index classified patients for their cardio-metabolic risk like the original definition of the HTGW phenotype. MetS is a common global disorder comprising a cardio-metabolic cluster that predisposes to both type 2 diabetes mellitus (T2DM) and atherosclerotic cardiovascular disease (ASCVD). Recently it was shown, using this large National Health and Nutrition Examination Survey (NHANES) data set, that the ratio of triglycerides (TG) to high-density lipoprotein cholesterol (HDL-C) (TG:HDL-C) ratio is a better biomarker of MetS in AAs compared to the CRP:HDL-C ratio, despite their lower TG and higher CRP levels. In an attempt to improve the assessment of cardio-metabolic disease risk in AAs, in the present report, we compared, the TG.WC index to the TG:HDL-C ratio in AAs and NHWs in the large NHANES study to determine which is the superior biomarker for MetS.